Abstract:Taking the construction of a foreign large-scale bridge as a case, through the calculation of deformation value of topographic map projection, the accuracy error caused by using UTM projection coordinate system is analyzed. Therefore, the applicability of UTM projection and transverse Mercator projection in engineering is expounded. The steps, methods and accuracy verification process of establishing the engineering coordinate system are emphatically explained. At the same time, the coordinate transformation method of engineering coordinate system and UTM coordinate system is given, which can be referenced for the similar foreign engineering projects.